In his Analysis of Sensations, German Die Analyse der Empfindungen, Ernst Mach offeres this wonderful perspective: The world as he can see it (only to make things easier) through one of his eyes.
How do we know anything about the world? Can we find out whether are dreaming all this or whether we are actually incorporated in the bodies we feel? How do I know that this is "my" arm? And why do I assume that the window at the end of the room is also nor part of "me"?
Mach's answer was simple and radical: We do not actually know the answers to any of these questions in the classical sense of knowing. The point is rather that we have perceptions and that we interpret them. Things are "as if". If I "move my arm"; I see something moving and have a number of other sensations associated. It is my interpretation of these combined sensations that the arm belongs to me in a sense the window does not.
Science, so Mach, is an interptetation of data and should not be anything else. Good interpretations are simple and operable, they are "economically" organized, in that they do not include agents and essences of which we do not have any data and of which we cannot tell what difference they would make in an equation. Scientists should focus on the interpretation of data. Questions such as "Does God exist?" pose under this premise rather imaginary problems, "Scheinprobleme". Interpreting data we will never come across a transcendent being, a being transcending our experience.
Ernst Mach stood with these considerations (he spoke of "Empiriocriticsm") at the turning point of a development of thought Comte can be said to have triggered.
Eventually quite unlike Atheists and Marxist Materialists
What was interesting in Comte to 19th-century scientists was his rejection of problems - where Marxists and Atheists gave answers to questions one could not really answer. Comte, instead, focused on logic and mathematics as sciences designed to handle data. Materialists hardly knew how to integrate these fields of thought.
Comte's positivism inspired a special strata of fact oriented research - especially in the new field of literary history. It triggered the evolution of new schools of academic history. What was fruitful here was Comte's move towards an inclusion of developments: Mankind needed to go through them.
The late 19th-century development of a new theory of knowledge, as proposed by Heinrich Hertz and Ernst Mach, designed to bridge the gap between German idealism and modern materialism opened eventually the door into the field of 20th-century sciences. Materialism is not simply rejected with the considerations Hertz and Ernst Mach promoted at the turn into the 20th century. Our ideas of matter become an ideal interpretation of data, so the new point of view.
Albert Einstein eventually thanked Mach for his thoughts. They had opened him the road towards entirely new and different interpretations of data. If it is easier to explain certain phenomena with the help of a fourth dimension in our computations, then why should we not use such a dimension as a working premise? The idea of truth is abandoned here. The idea of useful interpretations of data wins as an option positivism brought about.
Any sound scientific theory, whether of time or of any other concept, should in my opinion be based on the most workable philosophy of science: the positivist approach put forward by Karl Popper and others. According to this way of thinking, a scientific theory is a mathematical model that describes and codifies the observations we make. A good theory will describe a large range of phenomena on the basis of a few simple postulates and will make definite predictions that can be tested [...] If one takes the positivist position, as I do, one cannot say what time actually is. All one can do is describe what has been found to be a very good mathematical model for time and say what predictions it makes.
Richard von Mises. Positivism: A Study In Human Understanding. Harvard University Press. Cambridge; Massachusetts: 1951.